Frank wrote:

Whenever I hear a BOOM (like a bomb blast) I know the whole neighborhood
goes down without power, either mine or another neighborhood down stream on
another feeder. That BOOM comes from an adjacent substation tripping a high
voltage, high current circuit breaker. So breakers do go BOOM, just not the
little house breakers.

Since all it turned out to be was a loose wire, I can only assume the
boom that I heard was actually a door slamming. That door slam then
rattled the wire just enough to become undone, and thus breaking the
circuit...